3.6 Manual Starting: Fuel Pump Behaviour

XJ-S
1

Evening folks,

I’ve got a query about what should be happening with the fuel pump when I turn the ignition on - hopefully someone can confirm that my car is behaving properly.

My 3.6 manual had been standing for about 3 years without being started - it started fine and I drove it into my garage about 6 months ago and recently tried to get it started again, but although it would turn over, it wouldn’t fire. and no fuel is getting to the engine.

I’m fairly sure that this has been caused by sediment or rust in the fuel tank which has blocked the fuel system and caused the pump to fail. I checked today and found that almost immediately after turning the ignition on, the fuel pump receives 12v and then about 5 seconds later I can hear the relay click and the supply turns off. The pump doesn’t run at all when connected so is in need of replacement but is that electrical behaviour correct?

I’ve ordered a new pump and will fit it in due course - I’ll also empty the fuel tank tank and swirl pot out and clean through the pipework before adding new fuel.

As I’ve discussed elsewhere in another thread, this car is facing an uncertain future and may end up being used for parts, but I’d like to get it moving so that I can move it about the garage and also prove that the engine is healthy.

Many thanks everyone :slight_smile:

Simon.

2

Not sure about the XJ-S but with the XJ40 (same engine) the fuel pump primes but less than 5 seconds, its about 2 from memory, and then shut off until the starter is activated.

3

Simon,

I would like to congratulate you the idea of starting the AJ6 engie straight away after 3 years of sleep. Feel yourself extremely lucky that your fuel pump refused to do it.
Without going into details, first I suggest this before further attempts - especially that your profile shows that you’re XJS may be UK-based:

Now going back to your fuel pump - I suggest giving it few whacks with mallet and checking pump terminals for any presence of oxy. Relay works fine, you’ve checked the voltage on the pump already so carry on with few bangs. If you haven’t poured any stabiliser into the tank - fresh fuel is strongly recommended or maybe even mandatory (1.5 year expiry time usually)

Expect some issues with electrics and brakes…